JPS58206844A - Device for controlling supply of fuel for internal- combustion engine - Google Patents

Abstract

PURPOSE:To prevent excessive dilution of a gaseous mixture during the acceleration and improve the acceleration function of the titled device by detecting the position of a piston valve of a suction air throttling device and carrying out an optimum fuel increase in quantity during the accleration of the engine in accordance with the detection result. CONSTITUTION:A variable Venturi type carbureter is designed so that the negative pressure at the downstream of a piston valve 5 undergoes change in accordance with the air flow quantity within a suction air path 18 varying according to the opening degree of a butterfly valve 11. This varying negative pressure is introduced into a negative pressure chamber 19 via a communicating path 17, whereby the piston valve 5 makes an up and down movement, and the opening area of a needle jet 3 is made variable. In this case, measuring members 21 and 22 which are made variable in their relative positions, are provided in the piston valve 5 and a stationary member, and position sensors (not shown) each of which consists of a differential transformer and the like are provided in the same members 21 and 22. The acceleration quantity increasing degree of the fuel is calculated from the outputs from these position sensors to control the fuel supply system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply control device for an internal combustion engine, and particularly to a fuel supply control device for an internal combustion engine, which is installed in an air intake passage and controls the fuel supply during acceleration by adjusting the position of a piston valve of a next intake air throttle device. It is something to do.

In conventional internal combustion engines, whether the type uses a carburetor or the type in which fuel is injected into the intake passage, the fuel flow rate in the steady operating range is 81I (for example, the standard 0 for three-way catalysts). For various reasons, such as the center of gravity being placed in the center of gravity (feedback control, etc.) and delays in the operation of various configuration means, the transient response during acceleration is not sufficient. By detecting the position of the engine, it is possible to optimally increase the fuel supply to the engine rotational speed.

To explain the figures, FIG. 1 is a side sectional view of an electronically controlled carburetor as a first embodiment, and shows engine operating parameters (throttle opening, intake pipe internal pressure, engine rotation speed,
This is a variable venturi carburetor that controls the fuel supply according to atmospheric conditions such as engine temperature, pressure, temperature, humidity, etc.), and sucks air into the intake passage 18 as shown by arrow F. 1 is a float chamber. 21 dollar valve, 2 is valve seat, 6 is 21 dollar valve, 4 is straight needle, 5
is a piston valve, 6 is a diaphragm, 7 is a return spring, 8 is a pilot screw, 9 is a pilot outlet, 10 is a bypass outlet, 11vi
Butterfly valve, 12 is a float, 16 is a float arm, 14 i/i pilot jet, 15 is a main jet for lenoid, 16 is a lenoid valve, 17 is a communication path in the piston pulp, 18 is an intake path, 19 is a negative pressure chamber , 20 indicate atmospheric chambers, respectively.

Due to the change in the opening degree of the butterfly valve 11, the air at in the intake passage 18 changes, and the negative pressure below the piston pulp 5 changes. This negative pressure is communicated with a negative pressure chamber 19 through a communication passage 17, and the differential pressure with the atmosphere in the atmospheric pressure chamber 20 acts on the diaphragm 6, and as the negative pressure changes, combined with the operation of the return spring, the piston Valve 5 moves up and down.

In this invention, the illustrated members 21 and 22 are provided with a position sensor 1.
This method calculates the degree of fuel acceleration increase based on the position of the piston pulp. The position sensor may be an analog sensor (differential transformer, capacitive displacement meter, etc.), but
It is based on digital sensors so that it can be easily processed by digital computer computers. What can be used is (1) 1 optical switch such as a phototransistor! H)
There are means for indirectly adjusting the piston valve position rIt by detecting it with a magnetic switch such as a Hall element, a contact switch such as a microswitch, or a (1v) nozzle negative pressure pressure sensor.

Figure 2 (Al is a t-diagram with time on the horizontal axis and piston valve position S on the vertical axis, ('b) is a t-diagram with time t on the horizontal axis and throttle opening H'f on the river. So, first of all, if we assume FvJwoD that we are traveling at a constant speed with a constant throttle opening, then the piston valve position will be A.Now, when we press the accelerator, we will change the throttle opening at a constant speed of E. When the pressure is increased to position F, the instantaneous negative pressure during acceleration increases, the piston valve position temporarily rises rapidly as shown in C, and then,
It will gradually converge to the new standing location B. In this invention, as described above, the digital switch provided at an appropriate position detects the upward passage of the piston valve, and the degree of acceleration increase is calculated based on the number of passages.

FIG. 6 is a diagram showing a second embodiment of the invention,
This is a type that injects fuel into the intake passage. In the figure, 60 is an intake path, 61 is a piston pulp, 32 is a throttle valve, 6 is a natural injection valve, 34 is a rod, 65 is a diaphragm, 66 is a return spring, 67 is a performance body, 68 is a pickup part, 41 is a negative pressure passage, 42 is a negative pressure chamber, and 46 is an atmospheric pressure chamber. The action of moving the piston pulp up and down is the same as in the case of Figure 1.

(Incidentally, this piston and the means for horizontally narrowing this position may be collectively referred to as an acceleration sensor 5゛0.) If a digital computer is used in the control section, it is basically a digital sensor (a photoelectric sensor such as a phototransistor). Switches or magnetic switches such as Hall elements) are used in series.

FIG. 4 is an enlarged explanatory diagram of an example of the sensor, and the ejector body 67 has many teeth 69. ..., the pickup section 3
The tooth position is detected by the pickup 40 of No. 8.

In many conventional electronically controlled single fuel injection systems, from low speed,
When accelerating suddenly, the air-fuel mixture becomes dizzy for a moment, making it impossible to obtain a smooth increase in torque. The reasons for this are: (1) Delay caused by missing term injection, where one injection is made in one rotation per engine revolution.

(11) Delays in intake air (A/D conversion timing, sensor response delays! 1.) (iii) Delays due to processing time in arithmetic units, etc. can be considered; Wi-visible 4'n
However, (1) will be explained first. Figure 11g5 is an explanatory diagram showing 1. Take the crank angle to the skin, and say 1
&2,7≦6. The explanation will be based on the case of a four-cylinder cylinder.

J,, J,, J, is fuel injection at Maura of 660°□
It is standing. Then, at the position of point G shown by line 11, 71
Become a friend, starting with the 11th speed. 'rll 'r21 T3 *
'r, l T5... is the ignition position of each cylinder, K, l K! rK3 rK4. To...
・, C indicates the opening period of each cylinder's intake valve.

Even if you start accelerating at point G, the injection state changes.
, but at that time, in the section 3, the suction 1 has already been reached.
This is the final stage of the process, and it is from Kirito T4 onwards that normal combustion occurs for a while. If the ignition is TI + T2tT up to that time, there is a possibility that an abnormal combustion condition will occur due to the lean air mixture. That is, there is a response delay n of two rotations at maximum.

If the engine speed is 1ooo r,, p, m, 120
There is a microsecond delay. As a countermeasure against this delay, currently, in addition to synchronous injection, so-called sequential injection is used, in which each cylinder injects asynchronously and independently injects each cylinder. However, the sequential injection requires an independent injector drive circuit, etc. for the air pump 11#m, resulting in high costs. Next, to explain (II), a variable sensor such as an air flow sensor or a pressure sensor is used to output t% of intake air, but generally there is a response delay of about 20 to 50 microseconds. A/D of analog data
Determines the need to perform a conversion. Ideally, you always want 1 & new air volume data, but if you always do A/D conversion,
Since other arithmetic processing of the device will be delayed, samples are taken periodically after a period of time when they are actually applied, or the samples are sampled in synchronization with engine rotation.

For example, if the engine rotation is synchronized and A/D conversion is performed once per rotation, there will be a maximum delay of one rotation - engine rotation speed 1000 r, p
, m, there is a delay of 60 microseconds. That is, [
The response delay fL of the sensor] and the ``difference in the A-/D 4i conversion timing'' result in a total maximum delay of 110 microseconds (approximately 2 revolutions when the engine rotation is 1000 r, p, m). In this way, from the start of Yu station acceleration, up to 4
The air-fuel mixture was extremely lean during two revolutions at + and even rotation. This invention solves this drawback as much as the piston valve as mentioned above! liK controls the injection t to prevent the air-fuel mixture from becoming lean.

Figure 6 is an explanatory diagram of the basic principle of the acceleration sensor. (Slope is the relationship between time T and throttle opening H, S) is the relationship between time T and piston valve position S, and (C) is time T
and venturi negative pressure p! The throttle opening is at the initial position, and at the acceleration time point E, the opening opens to a new state F. The piston pulp position is initially at position A, rapidly rises at the 0 point as it accelerates, and then gradually converges to a new position B. The sharper the acceleration, the higher the peak at the 0 point, as shown by the dotted line. In other words, the acceleration at 100 is more rapid than at L1. Next, let's talk about Bae/Churi Chaiatsu.
From the first turn on, it rapidly rises to 0 points during acceleration, and gradually converges to 8 points. The higher the speed of the sword, the sharper the mountain becomes, as shown by the dotted line.
become concerned. In other words, the mouth speed is higher at Δf2 than at Δf1. It can also be used as an acceleration sensor by turning the pressure switch on and off in response to one turn of a predetermined negative pressure ΔP, and by knowing the on-time of the pressure switch.

Seventh! The figure is an explanatory diagram showing the relationship between throttle position III and acceleration sensor output, etc., and all figures are shown on the horizontal axis as crank! AGA is taken, on the vertical axis (a) is the throttle opening H, Φ) is the actual intake air tQ, (c) is the intake air measurement 1M, (d) is the injector pulse width,
(e) shows the piston valve 4: device S, and (f) shows the acceleration sensor output P, respectively. Comparing Φ) and (c)e, in (b), the actual intake air amount Q is at the Karo speed point G
However, in (C), the measured impurity M begins to increase after 20 to 110 microseconds, as mentioned above. As shown in (d) and (f), the injection amount increase IW is determined according to the number of output pulses of the acceleration sensor. For example, the number of pulses is large during a sudden acceleration, and the number of pulses is small during slow acceleration, so the degree of increase is small.After that, until the termination condition is met, the basic Uζ is The prize money will be paid at a fixed rate.

In (C), the increased amount is shown by the part where 7 stitches were applied n1
Ryu's first is once asynchronously (also 1 and 2) every 7 days indicated by N and F.
times) and then increase the amount synchronously as shown by fl and F.

FIG. 8 is a schematic illustration q of the second embodiment,
The air-fuel mixture is sucked into the engine 70 from the intake passage 60 via the intake valve 51. 62 is a throttle etc., and 33 is an injector. Air is drawn from the cleaner 55 through the surge tank 54. 50 tobacco invention/Jll
It is a speed sensor.

Fuel: 60 fuel tanks, 1 fuel tank, 6 filters
2. Sends to injector = 63 via fuel pump 66 n
Ru. The excess fuel is provided by the regulator 64 and the return passage 6.
5 to allow the flow to flow back into the tank 60. The signal from the acceleration sensor 50 is input to the control unit, and the signal from there is sent to the relay field f'rF and connected to the fuel pump 66.
Efter 53 Hals width k 7gl <H sul. Direction control unit +l is atmospheric pressure AP, signal S゜M1 from idle switch, ignition 1 (pressure IV, pressure P1 from pressure sensor 52, opening degree S1 of throttle valve 32 by potentiometer, signal t4 from temperature detector 56) This is done manually.

[Brief explanation of drawings]

Figure 1 is a side sectional view of the carburetor, Figure 2 (a))
are explanatory diagrams of changes in piston valve position and throttle opening, respectively, Fig. 3 is an explanatory diagram of the second actual relaxation state of this invention, Fig. 4 is an enlarged explanatory diagram of the acceleration sensor, and Fig. 5 is an explanatory diagram of the second actual relaxation state of this invention. Explanatory diagram of the ignition timing of the receiving engine, Figure 6 (a), (b),
(C)! d, explanatory diagram of changes in throttle opening, piston valve position, and venturi negative pressure, respectively, No. 7J(a), (
b), (C), (d), (el), (f) fl Tenten,
1.0 t, opening degree, actual intake air amount, measured amount of intake air,
Explanatory diagram of changes in injector pulse width, piston valve position, and acceleration sensor output with respect to crank angle, No. 8
The figures each show a schematic illustration of a second embodiment of the invention. Explanation of the basic code 5... Piston valve, 21.22...! 11j constant part 1 dimension, 31...piston valve, 53...fuel-
R shooting machine, 67...Mock body, 68...Pickup section, 40...Pickup, 50...Noguchi Speed Senna-
0 Agent W-Buji (8107) 1Esaf/'#Takashi (li
d・3 people) No. 211 No. 3 Figure 1114 Figure 1115 Figure

Claims (1)

[Claims] Fuel supply control for an internal combustion engine, characterized in that the position of a piston pulp of an intake air throttle device installed in an air intake path of the internal combustion engine is detected to control the fuel supply at engine jaw speed. Device.